Koeppe R E, Krieger M, Stroud R M
Biochim Biophys Acta. 1977 Apr 12;481(2):617-21. doi: 10.1016/0005-2744(77)90294-7.
A possible source of discrepancy between kinetic and spectroscopic studies of the active site ionizations in the enzyme trypsin (EC 3.4.21.4) could arise if a slow pH-dependent conformational change affected the rates at low pH. No such effect is observed within the time range of 1 min- 3 h when pre-incubation of trypsin at pH 2.0 or at pH 6.9 precedes the enzymatic hydrolysis of Nalpha-carbobenzoxy-L-lysine-p-nitrophenyl ester. The deacylation rate of this hydrolysis depends on a single pKa on the enzyme between pH 3 and pH 7.
如果一种缓慢的pH依赖性构象变化在低pH值下影响了反应速率，那么在胰蛋白酶（EC 3.4.21.4）活性位点电离的动力学和光谱学研究之间可能会出现差异来源。当在Nα-苄氧羰基-L-赖氨酸对硝基苯酯的酶促水解之前，将胰蛋白酶在pH 2.0或pH 6.9下预孵育时，在1分钟至3小时的时间范围内未观察到这种影响。这种水解的脱酰基速率取决于pH值在3至7之间时酶上的单一pKa。
